1. Field of the Invention
The present invention relates to a vertical cutting metal-working machine, and more specifically to a column and Z-axis slide mounting arrangement for a vertical cutting metal-working machine.
2. Description of the Prior Art
A regular cutting metal-working machine, as shown in FIG. 1, is comprised of a work table 3, a column 1 vertically disposed at one side of the work table 3, a longitudinal slide mounted on the work table 3 and adjusted in Y-axis direction, a cross slide 4 mounted on the longitudinal slide to hold the workpiece to be processed and adjusted in X-axis direction, a vertical slide 2 mounted on the column 1 and adjusted in Z-axis direction, and a rotary tool holder 21 mounted in the vertical slide 2 to hold a metal cutting tool. Referring to FIGS. 2 and 3, the vertical slide 2 comprises two parallel rails 221 bilaterally longitudinally raised from its back side wall and defining a longitudinal coupling groove 22, and a longitudinal coupling flange 222 of smoothly arched cross section raised from its back side wall on the middle between the parallel rails 221. The longitudinal coupling flange 222 defines a longitudinal coupling hole 223 for coupling to drive means. The column 1 comprises a vertical track 11 of T-shaped cross section formed integral with its front side wall and connected to the work table 3 at right angles, and a longitudinal coupling groove 12 longitudinally formed at the front side wall of the vertical track 11 on the middle. During assembly process, the longitudinal coupling flange 22 of the vertical slide 2 is inserted into the coupling groove 12 at the vertical track 11 of the column 1, enabling the vertical track 11 to be inserted into the longitudinal coupling groove 22 of the vertical slide 2, then two locating plates 23 are respectively securely fastened to the parallel rails 221 of the vertical slide 2 and disposed in contact with the vertical track 11 at a back side, enabling the vertical slide 2 to be secured to and moved along the vertical track 11, and then the longitudinal center mounting hole 223 of the longitudinal coupling flange 222 of the vertical slide 2 is fixedly connected to a driving device 13 (for example a screw rod, hydraulic cylinder, etc.), for enabling the vertical slide 2 to be moved up and down along the vertical track 11 by the driving device 13. Further, wearing pads 24 are securely mounted on the vertical track 11 and respectively disposed in contact with the locating plates 23, enabling the locating plates 23 to be smoothly moved with the vertical slide 2 along the vertical track 11. This column and vertical slide (Z-axis slide) mounting arrangement has numerous drawbacks as outlined hereinafter.
1. Because the vertical slide 2 is a heavy metal frame having a heavy rotary tool holder 21 in it and, because the vertical slide 2 (the longitudinal coupling groove 22) has a limited height, the vertical slide 2 tends to vibrate when moved along the vertical track 11. In order to eliminate this problem, the height of the vertical slide 2 may be made relatively greater. However, the vertical stroke of the tool is relatively shortened if the height of the vertical slide 2 is made relatively greater without increasing the vertical length of the vertical track 11 of the column 1. PA0 2. Because the two locating plates 23 are respectively securely fastened to the parallel rails 221 of the vertical slide 2 to support the vertical slide 2 on the vertical track 11, the locating plates 23 tend to be forced to deform, causing the vertical slide 2 unable to be smoothly moved along the vertical track 2. PA0 3. Because the locating plates 23 are separately made and then respectively fastened to the rails 221 of the vertical slide 2 to support the vertical slide 2 on the vertical track 11, the coupling precision between the vertical slide 2 and the vertical track 11 is difficult to be accurately controlled.